CD56 expression in T-cell acute lymphoblastic leukemia is associated with non-thymic phenotype and resistance to induction therapy but no inferior survival after risk-adapted therapy

Abstract

BackgroundExpression of CD56 has been associated with poor prognosis in acute myeloid leukemia and aggressive lymphoma. Design and MethodsWe analyzed the impact of CD56 expression in a cohort of 452 newly diagnosed adult Tcell acute lymphoblastic leukemia (T-ALL) patients; clinical data were available for 306 patients. Treatment was according to the GMALL study protocols 06/99 and 07/03 stipulating stratification into standard (thymic T-ALL) and high risk (pre-and mature T-ALL) groups. ResultsCD56 expression was detected in 63/452 (13.9%) patients. CD56+ T-ALL were predominantly of non-thymic (pre-T 35%, mature 41%) immunophenotypic subtypes, whereas 53% of the CD56 -cases were thymic T-ALL (p=0.00002). CD13, CD33, CD34 and HLA-DR were significantly more frequently expressed. A clonal T-cell receptor rearrangement was detected in 22/23 CD56 + ALL. No major clinical differences were observed at presentation. Treatment of CD56 + ALL resulted in a lower rate of complete remissions (70% vs. 88%) (p=0.001) and a higher rate of resistant disease (21% vs. 8%) (p=0.004). CD56 expression had no significant influence on overall (48% vs. 59%) and disease free survival (67% vs. 57%) at three years. ConclusionsCD56 is expressed on a subset of adult T-ALL with distinct immunophenotypical features and higher resistance to therapy. Most CD56 + ALL were treated in the high-risk arm of the GMALL study protocols owing to their non-thymic phenotype. Thus after risk adapted treatment a prognostic impact of CD56 expression was not detectable.Key words: T-cell ALL, CD56, natural killer, immunophenotype. Haematologica 2009; 94:224-229. doi: 10.3324/haematol.13543 ©2009 Ferrata Storti Foundation. This is an open-access paper. Citation: Fischer L, Gökbuget N, Schwartz S, Burmeister T, Rieder H, Brüggemann M, Hoelzer D, and Thiel E. CD56 expression in T-cell acute lymphoblastic leukemia is associated with non-thymic phenotype and resistance to induction therapy but no inferior survival after risk-adapted therapy. CD56 expression in T-cell acute lymphoblastic leukemia is associated with non-thymic phenotype and resistance to induction therapy but no inferior survival after risk-adapted therapy

T-cell acute lymphoblastic leukemia with co-expression of CD56, CD34, CD117 and CD33: A case with poor prognosis

“…CD56 is a marker for natural killer (NK) cells, but is also expressed in neoplastic myeloid, lymphoid, plasmacytoid dendritic and myeloma cells, as well as in a minority of T cells (7). Co-expression of myeloid markers together with CD34 and CD56 in T-cell ALL is seen more frequently (6,7).…”

“…CD56 is a marker for natural killer (NK) cells, but is also expressed in neoplastic myeloid, lymphoid, plasmacytoid dendritic and myeloma cells, as well as in a minority of T cells (7). Co-expression of myeloid markers together with CD34 and CD56 in T-cell ALL is seen more frequently (6,7). To the best of our knowledge, this is the first report of aberrant co-expression of the NK cell marker CD56, the myeloid cell markers CD117 and CD33 and the stem cell marker CD34 in a patient with T-cell ALL.…”

Initial Diagnostic Workup of Acute Leukemia: Guideline From the College of American Pathologists and the American Society of Hematology

“…At diagnosis, morphologic evaluation is often performed and interpreted at the local institution, § § § § § § § often, with review of slides in a central laboratory or tertiary care center if part of a clinical trial, 25,411,415 or samples may be prepared and interpreted at a central laboratory or tertiary care center, 112,297,340,412,413 including any immunophenotypic or other studies required for diagnosis. 415 A discrepancy rate of 12% was reported between local and central review of AML diagnoses.…”

“…411 At diagnosis, flow cytometry testing may be performed at the primary institution, with results reviewed by a central laboratory or tertiary care center if part of a clinical trial, 14,324,415 or flow cytometry may be performed and interpreted at a central laboratory. 297,413 At diagnosis, cytogenetic testing may be performed and karyotypes interpreted at the primary institution********; cytogenetics may be performed, but karyotype images be reviewed at a central laboratory or tertiary care center, † † † † † † † † or all cytogenetic testing and interpretation may be performed at a central laboratory or a tertiary care center.…”

“…179 Fluorescence in situ hybridization studies as part of clinical trials were typically performed at a central laboratory or tertiary care center. 106,112,413,414 Molecular studies confirming mutations and gene rearrangements as part of clinical trials were typically performed at a central laboratory or tertiary care center § § § § § § § § as were DNA methylation studies. 196 If testing involves making specimens for routine or cytochemical staining or performing flow cytometry on BM at a central laboratory, the sample should be shipped overnight and processed within 24 hours of being obtained.…”